I just want to add that I live in the French Alps (3 hours away from the valley where Price studied his Swiss natives in the 1930's) and the cows have just this week been let out to pasture again after being inside barns for the winter. Whilst they are inside, their butter is pale yellow (because they eat hay that has been cut during the autumn) and soon the butter will be turning deeper yellow as they start eating fresh green grass again.

The movement of livestock is called 'transhumance' - where they are moved up to alpine quarters in the summer and are kept inside barns for the winter months.

I do not think it is the butter's color alone that should be an indication of its nutritional value, however; pastured butter is pastured butter, obviously better than intensively raised butter but the butter WAP was studying was alpine butter; made from milk that has been taken from cows who are pastured on the high alpine plateaux of Europe where the cows are completely free to eat medicinal flowers and all manner of other plants never found in the typical farmer's field (the cows get to choose what they eat - they are self-medicators).

Our butter tastes like no other butter I have ever tasted before and it's color/texture is never static, it turns from white to deep yellow throughout the year and the locals eat it when it is deep yellow (in the summer when the cows are high up on the mountains), it is also traditional in these parts to eat cheese when the butter is white - all the french mountain artisan cheese would have been made with summer milk and stored for consumption in the winter, insuring that the population receive the best nutrients all year round, the most expensive cheese here is still made with 'alpage milk'.

When it is in the fridge it is rock hard and when left on the counter, soft as margarine. I would be suspicious of butter that is soft even when in the fridge.

I am not sure about the butter in the U.S. but I would look for a farm outfit where the butter is produced 'by hand' so-to-speak and changes color throughout the year. If there are any 'artisan' dairies where you live, buy cheese in the winter and eat yellow butter in the summer (preferably from cows grazed on mountainous terrain where they have rough pasture containing a variety of different wild plants to eat).

I became a little skeptical of the gold butter craze when I read that the distinct orange color was from genetic selection for beta-carotene production in Guernsey cows.

From wikipedia: "The unique qualities of the milk produced by the Guernsey cow have made the breed world famous. The milk has a golden colour due to an exceptionally high content of beta carotene... From the 1950's to the early 1970's, Golden Guernsey trademark milk was sold in the US and Canada as a premium product. The golden color produced by beta carotene bound to the fat in the milk was the biggest marketing point and the source of the brand name. Only milk from Guernsey cows could be marketed under the Golden Guernsey trademark. The advent of homogenization and various changes to the way milk was priced and marketed, spelled the end of Golden Guernsey branded milk."

I've also seen first-hand that color varies greatly with diet, and diet varies greatly with season (despite our best efforts, grass just won't grow in the winter). This spring I started making my own butter from cream delivered by a local dairy. In early March when I made it for the very first time, the butter was disappointingly pale and even the same color as some Costco butter we had. Over the last few weeks, however, the butter has gotten noticeably darker. I think the cows have probably switched from cut and dried hay to fresh growing grass as the weather warmed up and they were able to pasture more. Price does make a point that the best butter was from cows in spring pasture.

Kerry gold butter is grassfed year round and has all the increased nutrients, normal butter is not orange. It still has vitamin A in it or the butter would be white. I don't think colour is a good guide by itself.

The fact that the butter is soft is a sign that it is from grassfed cows. The butter from grass fed cows has less saturated fat and and more unsaturated fats like alpha-linolenic acid and conjugated linoleic acid which have lower melting points making the butter softer.

Edit: PortlandAllen is correct the Irish cows would be fed hay or silage over the winter. Although Irish cattle can graze longer than most others in Europe or America due to the warmer, wetter climate. If you want butter from year round grass fed cows you'd have to get some New Zealand butter.

http://www.anchorbutter.com/AnchorButter.html

How do we make the richest smoothest creamiest-tasting butter?

We start with 100% fresh cream from cows that graze only in green pastures 365 days a year. We add nothing but a touch of salt. The fresh cream is slow churned torelease the water and then packed into blocks that are immediately frozen, locking in the freshness and rich buttery flavor. Butter from grass-fed free-ranging cows is higher in Omega 3, Vitamin A, and Beta Carotene, all proven to be good for your health. Additionally, our daily cows are absolutely hormone free.

As far as I know, the natural yellow of butter (not the additive yellow of most store-bought stuff) comes from the oxidization of vitamin A in the fat. The yellow is usually quite pale. I'm not sure what has to be done to butter to make it darker yellow or orange.

I bought both Kerrygold and a New Zealand brand to compare a while back and they were the same color yellow. Certainly not orange, but much more yellow than the Land O' Lakes crap that I had used in the past.

i make my own butter with cream from a completely pastured cow. it is quite yellow. i suspect that pale butter is from cows that have a controlled diet.

Not sure about the color thing either, but Kerrygold is awesome. It's my only butter now.

I use Kerrygold. It always hardens in my fridge.